| Significance | Code | Meaning |
|---|
| FIR | EGTT | London FIR | | | / | | | Qualifiers | Q | | | | RO | Overflying restriction | | | XX | miscellaneous plain language | | | / | | | Traffic | I | IFR traffic affected | | | V | VFR traffic affected | | | / | | | Purpose | N | For immediate attention of aircraft operators | | | B | For inclusion in Preflight Infomation Bulletins | | | O | Operationally significant for IFR flights | | | / | | | Scope | W | Navigational Warning | | | / | | | From flight level | 000 | Surface | | | / | | | Up to flight level | 009 | 900 feet QNE | | | / | | | Centre Latitude | 5150N | 51° 50' North' | | Centre Longitude | 00041W | 0° 41' West | | Radius of area affected | 002 | 2 nautical miles |
| | D BAND HIGH INTENSITY RADIO TRANSMISSION AREA ( HIRTA ) IN LOW FLYING AREA 5 AND NIGHT ROTARY REGION 4A AT POSITION 514946N 0004049W,( TRING,HERTFORDSHIRE ) RADIUS 1NM.MAXIMUM HEIGHT 530FT ABOVE GROUND LEVEL.24 / 08 / 247 / LFC SAFE DISTANCES CIVILIAN AIRCRAFT 0.1342 NM 170FT ABOVE GROUND LEVEL MILITARY AIRCRAFT SUSCEPTIBILITY VERY LOW 0.1166 NM 62FT ABOVE GROUND LEVEL LOW 0.1351 NM 174FT ABOVE GROUND LEVEL MEDIUM 0.1508 NM 270FT ABOVE GROUND LEVEL HIGH 0.1936 NM 530FT ABOVE GROUND LEVEL PULSE LOW NIL PULSE MEDIUM NIL PULSE HIGH NIL |
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